1. Field of the Invention
This invention relates to a photographic printing system, and more particularly relates to a photographic printing system for printing blow-ups which require high finishing accuracy.
2. Description of the Related Art
In photo studios where wedding pictures or the like are taken, enlargers of the type in which a focusing check is effected with the naked eye are generally employed (free focus type enlargers). In such photo studios, it is a requisite that blow-ups be prepared and that the subjects be arranged in an optimum manner in predetermined frame sizes. Further, in respect of the finish state of the prints, a higher image quality is required than in the case of taking ordinary snapshots. This is due to the fact that the greater the magnification of a picture, the more liable it becomes to errors in density and color balance. To overcome this, an analyzer is used to obtain correct data (printing condition data) from finished negative films.
Such an analyzer is used to adjust factors such as density and color balance to optimum values by picking up the image on a negative film with a CCD camera and displaying the image thus obtained on a CRT. The image displayed on the CRT is identical with the one to be printed on printing paper and it can be adjusted by the operator. Accordingly, the operator can visually determine, before the printing process, whether an optimum image can be printed on printing paper or not. The data thus adjusted can be supplied to the controller of a particular enlarger by storing it in a storing medium such as a floppy disk, and the printing can be performed at the enlarger in accordance with the data stored in the storing medium.
However, more than one enlarger may be installed in a photo studio; there may be a studio where a plurality of enlargers of different models are installed. When performing printing from the same negative film using these enlargers, based on the data obtained with the analyzer, slight differences may result from one and the same group of data, in density, color balance, etc., due to differences in the type of light source, the printing method (additive color process or subtractive color process), the type of dimmer filter and the finishing accuracy of the lens used. Even when the models are the same, any difference in the channels which are determined in accordance with the type of negative film, the film maker, the film sensitivity, the emulsion number of the printing paper, etc., will result in changed exposure conditions, so that a similar phenomenon may occur.